"The U.S. military has confirmed one thing: the physiological episodes (PEs) that pilots occasionally experience because of oxygen deprivation or decompression sickness present a “complex, perplexing issue,” to use the Navy’s words. A spate of recent incidents involving high-performance Navy as well as Air Force jets suggests that PEs are a recurring condition the services need to manage and not a problem they can simply fix.

There is also a wild card in the deck—the human in the loop known as the pilot. “There is no fixing the human; every human reacts differently to every situation,” Capt. Cliff Blumenberg, head of the Navy’s aerospace medicine branch, told reporters during a September teleconference. “Even the same person in the same aircraft on different days or different flights might experience a physiologic episode at one time and maybe not the next flight. It depends on what you’re doing, how hydrated you are, how well rested you are, what else is going on in your life. Do you have a mild cold that you didn’t recognize?”...

...Honeywell Aerospace, which supplies OBOGS on the F-35 and F-22 fighters as well as on other U.S. and international aircraft, referred questions on the F-35 to manufacturer Lockheed Martin."

"...The Navy’s F/A-18 Hornet, EA-18G Growler and T-45 Goshawk trainer as well as the Air Force’s new F-35A fleets have seen a significant surge in these so-called physiological episodes (PE) over the last few years. In the F/A-18 and EA-18G communities, the number of PEs increased almost eightfold from 2009 to 2016 and as of October was up to 108 for 2017 alone (see graph). In the T-45 fleet, PEs increased from just one in 2009 to 38 in 2012, and 29 have occurred so far this year (see graph). There were just 10 PEs in F-35As in 2006-16; in 2017, the Joint Program Office so far has recorded another 10, doubling the overall number reported (see infographic)....

...On the F-35A, one constant in the three most recent incidents at Luke AFB may prove key to solving the problem. In each of the incidents, initiating the backup oxygen system did not immediately ease pilots’ symptoms. This indicates that the problem is not true hypoxia, says Col. Ben Bishop, commander of the Air Force’s 56th Operations Group and an F-35 pilot.

Bishop believes pilots could be experiencing hypercapnia due to restricted breathing, potentially caused by the life-support system. He does not think the cause is hyperventilation.

“I think there might be something based on how the machine and the human are interacting that’s altering the breathing,” Bishop says.

The team is looking at all flight equipment for an indication of something that would restrict pilot breathing and taking steps to make the life-support system as robust as possible, he says. Already, the Air Force has made a number of changes to flight equipment to mitigate the potential for restrictions of breathing, including reducing the weight of the flight vest to making breathing easier and making changes to the exhalation valve on the mask to prevent sticking.

Bishop is confident the problem is not caused by air contamination or an OBOGS fault. There are no indications of carbon monoxide or other toxins on the ramp or during pilot examinations, he says. And recent testing of the OBOGS found the system is generating enough oxygen to safely support the pilot.

While initially there was a lot of concern in the pilot community at Luke over the PEs, pilots have begun to regain confidence both in the leadership and in the F-35, Bishop says. Today, although pilots realize the team may never find a single “smoking gun,” they have high confidence that in the event of a PE, they will be able to turn on the backup oxygen system and safely recover the aircraft, he stresses.

“We are not going to make any pilot that’s not comfortable flying the aircraft—who doesn’t have confidence in the F-35’s life-support system—we’re not going to make them fly,” Bishop says. “Up to this point, pilot confidence has been high enough that everyone has been able to return to fly.”"

I'm too lazy to spend an hour googling and searching, so I'll just ask...

Just what qualifies as a physiological event (PE)? Obviously, if a pilot passes out, that would be a significant PE. But what if a pilot notices a tingling on the back of his hand or in his fingertips? Does that count as a PE here?

I recall going for my ride in the altitude chamber at Pederson AFB. My personal sign was tingling in the middle tops of my thighs at 21,000 ft. I was still talking, could still understand a question and make a reply and later I could still read my writing, though it was a bit shaky / sloppy. But tingling in my thighs was my "take note" sign.

A year or two later I flew nonstop from Denver (KAPA) down to Tucson in a Bonanza. To save time (I was late), I filed IFR and flew as direct a route southwest over the Rockies. I recall flying at atleast 16,500' and, while I had a couple oxygen bottles with me, I flew without O2 for a little while, all while monitoring my O2 levels with a pulsoximeter. I saw my O2 levels drop to the high 80s (88-89), but found that with slow, deep breathing, I could get my O2 level to 92-93 easily. Then I put my canula back on. I never once felt the tingling in my thighs.

While I do not discredit the reports coming out from professional military pilots, and while I do not intend to belittle or demean the seriousness of truly life threatening PE events, I have to ask (for clarification if nothing else): are all the PE events being reported truly life threatening, super significant events? Has everyone become hyper vigilant over reporting PEs that every little thing is being reported, when in the past it was nothing?

Rather than a Garmin altitude watch, personally I'd rather have a pulseoximeter sensor (and backup) wired into my flightsuit with an easy to read indicator on the instrument panel or in my HUD / HMDS. Some sort of "Take me to the o-club, HAL" button would be nice.

Now I may be full of sh*t, and probably am. If so, disregard everything I've written. If each of these events is an "OMG... I can't breathe!" event, then yes, this is very serious.

Take an F-16, stir in A-7, dollop of F-117, gob of F-22, dash of F/A-18, sprinkle with AV-8B, stir well + bake. Whaddya get? F-35.

I think it is clear from various statements (I'm looking at the CAPT Joyner USN video) that PEs are a lot of things - that is part of the problem and why they are called PEs Physiological Events which can be a range of aircrew experiences. As Joyner mentions categorizing PEs was problematic until recently - reporting was all over the shop then difficult to manage reports until her new bureaucracy has standardized and investigated (ongoing) with various methodologies/corrections.

Sure you have experienced some symptoms and that is commendable that you did some training and education on the matter however one must realise that the fast jet environment is unique (except for spacecraft & pressure suits or diving).

IF one reads the material here (perhaps someone could collect it into one PDF to post here - it is 0145 my time so not me) then one may realise that there are many factors at work to manufacture a PE - what is the question again....?

OH OK you have gone to the extreme of the 'pilot passing out' (is that on wings graduation parade?) to other symptoms which I won't call minor because they are not - they are symptoms of something potentially life threatening in the fast jet enviromnet (finger tingling or blue finger tips for example).

Some new aircrew under training may report a PE when perhaps it is not a 'PE' but some other anxiety however if one is anxious in a fast jet environment - except for good cause - then one needs to reconsider being a fast jet pilot perhaps. Anyway better to be safe than sorry - IF IN DOUBT PUNCH OUT! - is my favourite saying from 40 odd years ago now. Always good to talk about it in the here and now rather than in some fanciful afterlife when lessons learnt probably irrelevant.

To be realistic always good to declare an emergency perhaps which can be downgraded to something lesser if required - no one needs to be embarrassed about reporting a problem. So I had an A4G Fire Warning Light which did not extinguish immediately the throttle was closed (out in the never never boondocks of Oz - the vast desert) so my wingie came up to have a look - no fire and the light went out as throttle increased to keep flying so my initial MAYDAY was downgraded to a PAN and everybody cleared out for me to land from a straight in approach to a NON NAS Nowra runway. No big deal.

After several investigations & further fire warning incidents it was found to be a cracked engine shroud IIRC - this incident described earlier in another thread I think but right now my brain is mush at 0215.

I have mentioned seeing another A4G pilot acting weird in flight / radio calls when in formation with an instructor at my back in a TA4G. The other guy was hyperventilating with the oxy under pressure getting to him. Calls to calm down were heeded and he got himself under control and we returned to base ASAP - calm and cool as cucumbers to talk about it.

I'm not only lazy but tired as all getout so I'll finish on that note - maybe I'll get a second wind tomorrow - PE and all.

steve2267 wrote:I'm too lazy to spend an hour googling and searching, so I'll just ask...

Just what qualifies as a physiological event (PE)? Obviously, if a pilot passes out, that would be a significant PE. But what if a pilot notices a tingling on the back of his hand or in his fingertips? Does that count as a PE here?

It might; depends on whether he or she chooses to declare it as such.

steve2267 wrote:I recall going for my ride in the altitude chamber at Pederson AFB. My personal sign was tingling in the middle tops of my thighs at 21,000 ft. I was still talking, could still understand a question and make a reply and later I could still read my writing, though it was a bit shaky / sloppy. But tingling in my thighs was my "take note" sign.

Mine was always my fingernails. They would start to turn blue. Hence, I cut the fingertips off of my gloves (which also gave me more tactile precision wrt which knob or switch I was touching without looking at said knob/switch.)

steve2267 wrote:While I do not discredit the reports coming out from professional military pilots, and while I do not intend to belittle or demean the seriousness of truly life threatening PE events, I have to ask (for clarification if nothing else): are all the PE events being reported truly life threatening, super significant events?

No.

steve2267 wrote:Has everyone become hyper vigilant over reporting PEs that every little thing is being reported, when in the past it was nothing?

neptune wrote:....there is a hole in the ground in Alaska with a F-22A in it, that we would desperately like to avoid, ever again!

That is why this is a serious matter and not to be taken lightly. And yet, the number of cases of PE's have gone through the roof. It makes me wonder if the TA-45, F/A-18C/D/E/F, F-35's have been broken all along, or, if not, then what changed? I don't think it helped matters that the F-22 had a real problem, the pilots reported or treated it as such, and yet were poo-pooed by the service that there was no problem when in fact there was. I think it is an area that may not have been paid as much attention to in the past as it is now. Pilots are becoming hyper-vigilant, and now there is an avalanche (perhaps too strong a word) of new data / reports that have to be sifted through. But the press runs around predicting, as usual, that the sky is falling.

Take an F-16, stir in A-7, dollop of F-117, gob of F-22, dash of F/A-18, sprinkle with AV-8B, stir well + bake. Whaddya get? F-35.

OBOGGS has been around in some form for a long, long time (like, decades) and has been used on many aircraft. The F-22 got the most press but it was hardly the first suspected case of pilot hypoxia.

When people are encouraged to report everything...they are going to report everything. The media is incapable of distinguishing between actual cases of hypoxia and reported 'physiological events' because they dont fully understand the difference between a reportable PE and real hypoxia and they dont have access to the case data that distinguishes the differences.

Should pilots report? Sure, helps figure out if there is something wrong in the various systems and if something is wrong, come to the best solution(s).

The center fuel tank can be jettisoned, whether or not an IRST is installed. But that tank is never jettisoned except in an emergency. The tank can also be swapped with / to other Super Hornets as deployments dictate, as it was with the TCS on the F-14As.

"A member of the Senate Armed Services Committee has introduced a bill calling for the secretary of the Navy to report to Congress every quarter on the service’s efforts to find answers regarding pilot hypoxia-like incidents. It’s a problem, she said, that became much more real and pressing to her after being put through a flight hypoxia simulation during a recent visit to Naval Air Station Norfolk, Virginia.

Sen. Joni Ernst, a Republican from Iowa, told reporters at her Capitol Hill office that her visit had included an orientation flight in an F/A-18 Hornet, one of the aircraft platforms most significantly affected by a spike in “physiological episodes” in the cockpit....

...Ernst said she participated in a hypoxia simulation in which she was strapped into a reduced-oxygen breathing device, or ROBD, a mask that allows the amount of oxygen flow to be controlled and reduced. The symptoms she experienced, she said, were “textbook.” “My face got hot and flushed, my fingers started tingling, I got numb. My legs started tingling. It was very hard to concentrate,” she said. “And they put us through a battery of questions and we had to answer. It was horrible.”

The experience, Ernst said, changed her perspective on the gravity of the problem and added to her conviction that the Navy should be required to make regular reports on its efforts to find the cause of the episodes and address it....

...She said she didn’t have any additional recommendations about how the Navy should conduct ongoing studies about the causes of the episodes, but said she supported precautionary steps while flight operations continued.

Earlier this fall, the head of the Navy’s new Physiological Episode Action Team, Rear Adm. Sara Joyner, briefed the media about steps the service is taking to solve the problem, including the installation of new oxygen monitoring systems aboard the T-45 and improved systems to replace parts likely to fail in aging Hornets...."